Motor lawn-mower.



I. H. DAVIS.

MOTOR LAWN MOWER.

APPLICATION FILED APR. 12. 1913. 1, 1 2%,214. Patented Jan.5,1915.

3 SHEETS-SHEET 1 I. H. DAVIS.

I MOTOR LAWN MOWER.

APPLICATION FILED APR. 12. 1913.

3 SHEETSSHBET 2.

I. H. DAVIS. MOTOR LAWN MOWER. APPLIGATION FILED APR.12, 1913.

Patented Jan. 5, 1915.

3 SHEETS-SHEET 3.

E STATES PENT ISAAC H. DAVIS, 0F BOSTON, MASSACHUSETTS, ASSIGNOR OFTWO-THIRDS TO H. H. WESTINGHOUSE, OF NEW YORK,N. Y.

MOTOR LAWN-MOWER.

k Specification of Letters Patent.

Application filed April 1 2, 1913. Serial No. 760,646.

To all whom it may concern:

Be it known that I, ISAAC H. DAVIS, a citizen of the United States, anda resident of Boston, in the county of Sufiolk and State ofMassachusetts, have invented certain new and useful Improvements inMotor Lawn- Mowers, of which the following is a specification.

This invention relates to motor driven lawn mowers and is embodied in anauto- (lynamic attachment comprising a'motor the frame of which isprovided with means for engaging the usual transverse tie rod forming apart of the mower frame, the motor including a shaft having one or moredriving wheels adapted to bear on and be supported by the perimeter ofone or both of the traction wheels of the mower, the driving wheelimparting rotary movement to the traction wheel. g

The objects and advantages of the invention will be more fully pointedout hereinafter.

Of the accompanying drawings :-Figure 1 represents a transversesectional view of a motor attachment embodying my invention, and aportion of a lawn mower to which it is applied. Fig.2 represents asection on line 2-2 of Fig. 1, and an elevation of the parts at the leftof said line. Fig. 3 represents an end view of a lawn mower equippedwith a motor attachment embodying .the'invention and differing in minorparticulars from the embodiment shown in Figs.,1 and '2. Fig. 4represents a front elevation of portions of the machine shown by Fig. 3,a part of Fig. 4 being a section on line 4- 4' of Fig. 3. Fig. 5represents a section on line 5-4) of Fig. 4. view of a gear toothed rimadapted to be applied to a traction wheel of a lawn mower and a portionof a driving wheel engaged therewith. Fig. 7 represents a fragmentaryview showing a part of the handle bar of the implement.

The same vreference characters indicate the same parts in all thefigures.

The frame of an ordinary lawn mower comprises the usual end plates 12located within the usual traction wheels 13 and connected by atransverse tie rod. 14, the traction wheels 13 being journaled on axlearms formed on' or attached to the end plates 12 as. usual. In'somemakes of lawn mowers the tie rod 14 is offset from the axes of. thetraction wheels as shown in Figs. 1 and 2,

Fig. 6 represents an edge wheel 32. It is obvious, however,

while in other makes the tie rod is in line with the axes of thetraction wheels "as shown by Figs. 3 and 4. In carrying out my inventionI mount upon the tie rod 14 a motor which is preferably of the internalcombustion air cooled type, the frame of the motor here shown forpurposes of illus.

tration including a combustion chamber 15, a crank casing 16, anelongated inner bearmg 17 extending crosswise of the implement, a gearhousing com osed of'two sections 18' connected by' bol s 19, one of saidsections forming a artof an enlargement 20 of the bearing 1 and an outerbearing 21 formed on the housing sections 18 and extending at rightangles with the inner bearing 17. The movable parts of the motor includethe usual crank shaft 22 journaled in the crank casing 16, anintermediate shaft 23 journaled in the inner bearing 17 and connectedwith the crank shaft P by gears 24 and 25, said intermediate shaft beingprovided with a worm 26, and a power-delivering shaft 27 journaledin theouter bearing 21 and provided with a worm wheel 28 meshing with the worm26. The intermediate shaft 23 is provided with the usual fly wheel 29.The motor frame is provided with means, for engaging the tiev rod 14,the engaging means being of such nature that the tie rod engaged therebysupports the motor.

In the embodiment of my invention shown by Figs. 1 and 2, a foot 30 isconnected by a pivot bolt 30* with an ear 30 on the motor frame, andisprovided with a recess 31 formed to receive the tie rod 14. The foot isrigidly attached to the tie rod by a set screw 30. The power-deliveringshaft 27 is extended to a point over one of the traction wheels andprovided with a driving wheel 32 which is adapted to bear ontheperimeter of the traction wheel and drive the latter. As shown by Fig.2, theshaft 27 is extended over each of the traction wheels at each endwith a driving that only and is provided one driving wheel may beprovided. The driving wheel 32 may have gear teeth adapted .to engagegear teeth for-med on the perimeter of the traction wheel, or thedriving wheel may be engaged with the traction wheel by friction, thedriving wheel having a suitable frictional surface which maybe composedof vulcanized fiber or other mate: rial; The driving wheel 32 isarranged to bear Patented Jan. 5, 1915.

. on practically the highest part of the perimeter of the traction wheeland is preferably not liable to disturb the balance of the lawn mowerand cause an imperfect cut of the grass by the cutting. mechamsm ofthelawn mower. The foot 30 engaged as shown with the tie rod: 14constitutes a fixed support on which the. motor frame is adapted tooscillate and. move the driving wheel 32 toward and from the perimeterof the traction wheel. Means are provided for yieldingly holding thedriving wheel 32 in a. predetermined position, and in the embodiment of.the invention now being described, in contact. with the perimeter of thetraction wheel,.said means being. a spring 33. connected with the upper.portion of. the foot 30 and adapted to exert pressure on the motor framein the direction indicated by the arrow in Fig. 1. Means operable by anattendant behind the mower are provided for moving the motor frame andshifting the driving wheel 32- from its. predetermined position, and. inthis case moving it outof contact with the friction wheel, said. meansincluding a cord; 34 or its equivalent, such as a chain, attached at oneend to themotor casing at 35, said cord being adapted to be pulled bythe operator to move the motor frame against the force of the spring 33.The cord 3% may be connected with a lever 36 fulcrumed at 37 on thehandle bar- 38. of the implement, said lever being movable in adirection indicated by the arrow in Fig. 7 to exert a: pull on the cord34, and being provided with a ratchet 38F! engaging one of a seriesofteeth 39 to lock the lever and maintain the tension on the. cord.

In the. embodiment of my invention shown by Figs. 3, 4 and 5, theconstruction is the same. as that shown by Figs. 1 and 2 with the,following. exceptions, first, the foot indicated by 30 is movablerelatively 'to the motor frame and isprovided with asquared shank 40.movable in a squared socketv 41 on the. motor frame. The foot 30 isadapted to engage a tie rod 14. which is in line with.

the axes of the traction wheels. A spring 42 surrounds the telescopicshank formed by the members. 40 and 41. and bears at one end on the foot30 and at its opposite end on a part of the motor frame, said springhaving a tendency to raise the motor frame and mo e the. driving wheel32 from contact with the traction wheel, the action in this respectbeing the reverse. from.that described in connection with Fig. l wherethe spring tends to press the driving Wheel against the traction wheel.The manually in; opposition to the.

9" P ess the drivingoperable means. actin spring 42 are adapted wheelagainst the perimeter of the traction wheel, said means including two,cords 34 Which may be attached to a lever 36 such as that shown in Fig.7, and passing under guide pulleys +1 on the foot 3O to eyes 45 on themotor frame.

Means are provided for automatically cleaning the. perimeter of thetraction wheel engaged by the driving wheel 32 and at a point adjacentto the driving wheel. Said means may be variously modified asillustrated by Figs. 1, 2 and 3;. Figs. 1- and 2 show a rotary brush l6attached to a shaft 47 which is journaled in bearings on. the motorframe and is connected by. gears L8 and 49 with the power-deliveringshaft 27, the brush 46 being in contact with the perimeter of thetraction wheel. and 2 I have also shown an. extension 50 of the exhaustpipe of the motor, said. extension being arranged to project a blast ofthe exhaust gases across the perimeter of the traction Wheel or againstsaid perimeter in such manner as to remove foreign matter therefrom.Fig. 3 shows a non-rotating brush 51 supported by the motor frame andbearing on the perimeter of the traction wheel.

The cleaning of the driven traction wheel is of much importance in alawn mower, the traction wheels of which are frequently thickly coatedwith short pieces of wet grass. These, and other accumulations offoreign matter, are readily removable, by either of the cleaning meansabove described.

The combustion chamber 15, of. the. motor is preferably solocated thatit is adapted to be cooled by air set in motion by the revolution of theusual. knife reel 52 of a lawn mower, so. that the air thus set inmotion has a cooling action on the combustion chamber and other parts ofthe motor. To prevent the wet grass. detached by the knives from beingthrown upon the motor,l provide a. curved screen 53 which is interposed.between the knife reel and the motor, said screen being of any suitable,foraminous construction. permitting the air to pass freely which permitsthe continued operation of the motor when the revolution of; the kniveson the, lawn mower is suddenly stopped by an obstacle. The latterstatement applies of ordinary. construction without requiring wheel isseparated from the traction wheel,

the driving Wheel then being brought into contact with the tractionwheel to enable the knives to cut an unusual heavy body of grass. cases,be pressed intermittently against the traction wheel to overcome theresistance of unusual heavy grass.

It will be seen that each of the embodiments of the invention shown bythe drawings is an autodynamic attachment adapted to be applied to thetie rod of a lawn mower any change or adaptation of the lawn mower toreceive the attachment, the attachment being readily removable to enablethe mato receive the pivot bolt 30 chine to be operated by hand asusual. It is obvious, however, that the motor frame may be permanentlysecured to the frame of the lawn mower, the latter being provided withspecial means for engagement with the motor frame. 1

When the driving wheel and the perimeter of the traction wheel areprovided with gear teeth, the teeth of the traction wheel may be formedon a resilient steel ring 55, Fig. 6, adapted to be applied to theperimeter of an ordinary traction wheel,'the elasticity of the ringenabling it to hug the perimeter of the wheel so that the ring may beapplied to Wheels slightly differing from each other in diameter.

As shown by Figs. 2 and 4, the driving wheel is adjustably secured tothe shaft 27 by suitable means such as a set screw 56, provisionbeingthus made for adapting the autodynamic attachment to lawn mowers ofdifferent lengths. r The worm and worm gear forming a part of thepower-transmitting mechanism constitute a practical and suitable meansof speed-reduction between the crank shaft and the power-deliveringshaft ofthe motor.

Means may be provided for adjusting the described attachment to adapt itto different sizes of traction wheels. This may be accomplished byproviding the foot 80 (Fig. 1) with a plurality of holes 55 each adaptedThe point of pivotal connection of themotor frame with the fixed foot 30may therefore be raised or lowered and enable the. driving wheel 3 2 toengage traction wheels of different diameters.

I claim:

1. The combination. with a wheeled implement having traction wheels anda frame in- The driving wheel may, in some cluding a transverse tie rod,of a motor the frame of which is provided with means for engaging saidtie rod, thepower delivering shaftof. the motor being provided with adriving-wheel adapted to bear on one of said traction wheels. 7

2. The combination with a Wheeled implement having traction wheels and aframe including a transverse tie rod, of a motor theframe of which isprovided with means for engaging the said tie rod, the power-deliveringshaft of the motor being provided with a driving-wheel adapted to bearon one of said traction wheels, the motor being movable independently ofthe frame to vary the position of the driving-wheel relatively to thetraction wheel.

3.. In combination, a wheeled implement having traction wheels and aframe includinga transverse tie rod, a motor, the frame ofwhich isprovided with means for engaging said tie rod, said means havingprovisions for permitting independent movements of the motor, adriving-wheel on the power-delivering shaft, of the motor adapted tobear on one of said traction Wheels, yielding means for-automaticallyholding the driving-wheel in a predetermined osition. relatively to thesaid traction w eel,

and manually operable means extending rearwardly from the acting meansand adapted to be operated by an attendant behind the implement formoving the drivingwheel from said position.

4. The combination with a wheeled imple ment having traction wheels anda frame including a transverse tie rod, of an automatic attach-mentcomprising a motor the frame of which has a foot adapted to-be supportedby the said tie rod, and a drivingwheel .on the power-delivering shaftof the motor, adapted to bear on and be supported by one of'saidtraction wheels.

5. The combination with a wheeled implement having traction wheels andaframe including a transverse tie rod, of an autodynamic attachmentcomprising a motor the frame of which has a foot adapted to be supportedby the said tie rod, and a drivingwheel on the power-delivering shaft ofthe motor, adapted to bear on and be supported by one of said tractionwheels, the foot having provisions for permitting independent movementsof the motor frame and drivingwheel relatively to the traction wheel.

6. The combination with a wheeled implement having traction wheels and aframe including a transverse tie rod, of an autodynamic attachmentcomprising a motor the frame of which has a foot adapted to be supported'by the said tie rod, and a drivingbeing such that the driving-wheel isadapted to bear on the upper portion of the perimeter of the tractionwheel substantially in the vertical plane of its axis.

7. In combination, a wheeled implement having traction wheels and aframe including a transverse tie rod, a motor the frame of which isprovided with means for engaging the said tie rod, a driving-wheel onthe all power-delivering shaft of the motor, adapted to bear on one ofsaid traction Wheels, the said engagement means having provisions forpermitting the motor frame and drivingwheel to move relatively to theimplement frame and traction wheel, yielding means for automaticallyholding the driving-wheel in a predetermined position relatively to thetraction wheel, and means extending rearwardly from the motor andoperable by an attendant behind the implement for changing the positionof the driving-wheel.

8. In combination, a wheeled implement having traction wheels and aframe including a transverse tie rod, a motor the frame of which isprovided with means for engaging the said tie rod, a driving-wheel onthepower delivering shaft of the motor adapt ed to bear on one of saidtraction wheels, the said engaging means having provisions forpermitting the motor frame and drivingwheel to move relatively to thetie rod and traction wheel, automatic means for yieldingly pressing thedriving-wheel inwardly against the traction wheel, and means operablebyan attendant for moving the driving wheel outwardly from the tractionwheel, 1

9; In combination, a Wheeled implement having traction wheels and aframe including a transverse tie rod, a motorthe frame of which has apivoted seat rigidly engaged with said tie rod, a driving-wheel on thepower-delivering shaft ofthe motor adapted to bear on a traction wheelof the implement, a springinterposed between the motor frame and seatand adapted to hold the driving-wheel in yielding engagement with thetractionwheel, and a manually operable device for separating thedriving-wheel from the traction Wheel.

10. In combination, a wheeled implement having traction wheels and aframe including a transverse tie rod, a motor the frame of which isprovided with means for engaging the said tie rod, a driving-wheel onthe power-delivering shaft of the motor, adapted to bear on one of saidtraction wheels, the said engaging means having provisions forpermitting. the motor frame and drivingwheel to move relatively to thetie rod and traction wheel, yielding means for automatfor engaging saidtie rod, and with inner and outer bearings at right angleswith eachother, and a gear housing, the motor having a crank shaft, anintermediate shaft journaled in the inner bearing, and geared to thecrank shaft, said intermediate shaft bee ing provided with a worm, and apower-delivering shaft j ournaled in the outer bearing and provided witha worm wheel meshing with said worm, and with a driving-wheel adapted toimpart forward motion to one of said traction wheels and to be supportedby said traction wheel.

12. The combination with a wheeled implement having traction wheels anda frame including a transverse tie rod, of a motor the frame of which isprovided with adjustable means for engaging the said tie rod, the:[JOWGf-dGllVGIlng shaft of the motor being provided with a drivingwheel and also adapted, by the adjustability of said engaging means, tobear on traction wheels of different diameters.

13. The combination with a Wheeled'implement having traction wheels anda frame including a transverse tie rod, of a motor the frame of which isprovided with means for engaging said tie rod, said motor having apower-delivering shaft and a drivingwheel thereon adapted to engage oneof said traction wheels, the motor being provided with speed-reducingconnections between the power-delivering shaft and the-crank shaft.

14. A wheeled implement having traction wheels and a frame including atransverse tie rod, having a resilient gear-toothed ring forming theperimeter of one of said traction wheels, combined with a motor mountedon the said tie rod and provided with a toothed driving-wheel meshingwith said ring.

In testimony whereof I have aflixed my signature, in presence of twowitnesses.

' ISAAC H. DAVIS.

Witnesses:

C. F. BRowN, I P W. PEZZETTI.

